Display device and manufacturing method thereof

ABSTRACT

A display device includes a substrate including a pixel area, a thin-film transistor formed on the substrate, a pixel electrode connected to the thin-film transistor, a common electrode formed on the pixel electrode, a space formed between the pixel electrode and the common electrode, and a roof layer formed on the common electrode. The common electrode and the roof layer include a protrusion protruding from at least one of an upper edge and a lower edge of the pixel area.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 10-2012-0048264, filed on May 7, 2012, the disclosure ofwhich is incorporated by reference herein in its entirety.

TECHNICAL FIELD

The present invention relates to a display device and a manufacturingmethod thereof. More particularly, the present invention relates to adisplay device that prevents or reduces light leakage near a liquidcrystal injection hole, and a manufacturing method thereof.

DISCUSSION OF THE RELATED ART

A liquid crystal display includes two substrates and a liquid crystallayer interposed between the substrates. An electric field is generatedin the liquid crystal layer by applying a voltage to field generatingelectrodes. The electric field adjusts the alignment of liquid crystalmolecules of the liquid crystal layer, allowing an image to bedisplayed.

A gate line transmitting a gate signal and a data line transmitting adata signal are formed in the liquid crystal display, and a thin-filmtransistor connected to the gate line, the data line, and a pixelelectrode may be formed. The liquid crystal display may further includea backlight, a light blocking member, a color filter, and a commonelectrode. Light leakage occurring in the liquid crystal display mayreduce the quality of displayed images.

SUMMARY

According to an exemplary embodiment of the present invention, a displaydevice includes a substrate including a pixel area, a thin-filmtransistor formed on the substrate, a pixel electrode connected to thethin-film transistor and formed in the pixel area, a common electrodeformed on the pixel electrode, a space formed between the pixelelectrode and the common electrode, a roof layer formed on the commonelectrode and made of an organic material, and an overcoat formed on theroof layer and sealing the space for each pixel area. The commonelectrode and the roof layer include a protrusion protruding from atleast one of an upper edge and a lower edge of the pixel area.

According to an exemplary embodiment of the present invention, amanufacturing method of a display device includes forming a thin-filmtransistor on a substrate including a pixel area, forming a pixelelectrode connected to the thin-film transistor in the pixel area,forming a sacrificial layer on the pixel electrode, forming a commonelectrode covering an upper surface, a left surface, and a right surfaceof the sacrificial layer, forming a roof layer of an organic material onthe common electrode, patterning the roof layer and the common electrodeto expose the sacrificial layer on the upper edge and lower edge of thepixel area, thereby forming a liquid crystal injection hole, removingthe sacrificial layer to form a space between the pixel electrode andthe common electrode, injecting a liquid crystal layer in the spacethrough the liquid crystal injection hole, and forming an overcoat onthe roof layer to seal the space for the pixel area. The liquid crystalinjection hole, the overcoat and the common electrode are patterned suchthat the overcoat and the common electrode include a protrusionprotruding from at least one of the upper edge and the lower edge of thepixel area.

According to an exemplary embodiment of the present invention, thecommon electrode and the roof layer in a pixel area include a protrusionnear the liquid crystal injection hole such that a meniscus of theliquid crystal layer is disposed outside of the pixel area, which mayreduce or prevent light leakage near the liquid crystal injection holein the pixel area.

According to an exemplary embodiment of the present invention,transmissive axes of the polarizers are parallel or perpendicular to theupper edge and the lower edge of the pixel area such that light leakagemay be prevented or reduced at the edges of the pixel area.

According to an exemplary embodiment of the present invention, a pixelarea of a display device includes a pixel electrode, a common electrode,and a liquid crystal layer disposed between the pixel electrode and thecommon electrode. A meniscus of the liquid crystal layer extends beyondan outer periphery of the pixel area.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of exemplary embodiments of the presentinvention will become more apparent by describing in detail exemplaryembodiments thereof with reference to the accompanying drawings, inwhich:

FIG. 1 is a top plan view of one pixel of a display device, according toan exemplary embodiment of the present invention.

FIG. 2 is a cross-sectional view of one pixel of a display device takenalong line II-II of FIG. 1, according to an exemplary embodiment of thepresent invention.

FIG. 3 is a cross-sectional view of one pixel of a display device takenalong line III-III of FIG. 1, according to an exemplary embodiment ofthe present invention.

FIG. 4 is a top plan view of an initial alignment state of liquidcrystal molecules of one pixel of a display device, according to anexemplary embodiment of the present invention.

FIGS. 5-11 are top plan views of a display device, according toexemplary embodiments of the present invention.

FIGS. 12, 14, 16, 18, 20, and 22 are processing plan views of amanufacturing method of a display device, according to an exemplaryembodiment of the present invention.

FIGS. 13, 15, 17, 19, 21, and 23 are processing cross-sectional views ofa manufacturing method of a display device, according to an exemplaryembodiment of the present invention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described morefully hereinafter with reference to the accompanying drawings. Likereference numerals may refer to like elements throughout theaccompanying drawings.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent.

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIGS. 1 to 4.

FIG. 1 is a top plan view of one pixel of a display device, according toan exemplary embodiment of the present invention. FIG. 2 is across-sectional view of one pixel of a display device, according to anexemplary embodiment of the present invention taken along line II-II ofFIG. 1. FIG. 3 is a cross-sectional view of one pixel of a displaydevice, according to an exemplary embodiment of the present inventiontaken along line III-III of FIG. 1.

A display device according to the exemplary embodiment shown in FIG. 1includes a gate line 121 formed in a first direction, and a data line171 formed in a second direction crossing the first direction on asubstrate 110. The substrate may be made of, for example, glass orplastic.

The substrate 110 includes a plurality of pixel areas P, and theplurality of pixel areas P may be arranged in a matrix shape defined bythe gate lines 121 and the data lines 171.

Each gate line 121 extends in a transverse direction, or substantiallyin a transverse direction and transmits a gate signal. The gate lines121 include a gate electrode 124 protruding therefrom. The gateelectrode 124 is applied with the gate signal through the gate line 121.

A storage electrode 133 may be formed in the pixel area P. The storageelectrode 133 is not connected to the gate line 121 or the gateelectrode 124, and may be formed in a direction parallel to, orsubstantially parallel to the data line 171. Alternatively, the storageelectrode 133 may be formed in a direction parallel to, or substantiallyparallel to the gate line 121. A plurality of storage electrodes 133formed in the neighboring pixel areas P may be connected to each other.The storage electrode 133 may be applied with a predetermined voltagesuch as, for example, a common voltage.

As shown in FIG. 2, a gate insulating layer 140 is formed on the gateline 121, the gate electrode 124, and the storage electrode 133. Thegate insulating layer 140 may be made of an inorganic insulatingmaterial such as, for example, silicon nitride (SiNx) or silicon oxide(SiOx). The gate insulating layer 140 may be a single layer or amultilayer.

A semiconductor layer 150 is formed on the gate insulating layer 140.The semiconductor layer 150 may be positioned on the gate electrode 124,and may be extended under the data line 171. The semiconductor layer 150may be made of, for example, amorphous silicon, polycrystalline silicon,or a metal oxide.

A source electrode 173 protruding from the data line 171, and a drainelectrode 175 separated from the source electrode 173, are formed on thesemiconductor layer 150.

The data line 171 extends in a longitudinal direction, or substantiallylongitudinal direction and transmits a data signal. The data signaltransmitted to the data line 171 is applied to the source electrode 173.

The gate electrode 124, the semiconductor layer 150, the sourceelectrode 173, and the drain electrode 175 form one thin-filmtransistor. When the thin-film transistor is in an on state, the datasignal applied to the source electrode 173 is transmitted to the drainelectrode 175.

A passivation layer 180 is formed on the data line 171, the sourceelectrode 173, the drain electrode 175, and the exposed semiconductorlayer 150 between the drain electrode 175 and the source electrode 173.The passivation layer 180 may be made of, for example, an organicinsulating material or an inorganic insulating material, and may be asingle layer or a multilayer.

A color filter 230 is formed in each pixel area P on the passivationlayer 180. Each of the color filters 230 may display a primary color(e.g., red, green, or blue), however the color filters 230 are notlimited thereto. For example, the color filters 230 may also displaycolors such as, for example, cyan, magenta, yellow, or other colorsincluding white.

A light blocking member 220 is formed in a region between theneighboring color filters 230. The light blocking member 220 is formedon the boundary of the pixel area P and the thin-film transistor, and asa result, may prevent light leakage.

A first insulating layer 240 may be formed on the color filter 230 andthe light blocking member 220. The first insulating layer 240 may bemade of an inorganic insulating material such as, for example, siliconnitride (SiNx) or silicon oxide (SiOx). The first insulating layer 240protects the color filter 230 and the light blocking member 220.Exemplary embodiments may not include the first insulating layer 240.

The first insulating layer 240, the light blocking member 220, and thepassivation layer 180 have a contact hole 181 exposing a portion of thedrain electrode 175. In an exemplary embodiment, the contact hole 181may be formed in the color filter 230 instead of the light blockingmember 220.

A pixel electrode 191 connected to the drain electrode 175 through thecontact hole 181 is formed on the first insulating layer 240. The pixelelectrode 191 is formed in each pixel area (P), and is connected to thedrain electrode 175, thereby receiving the data signal from the drainelectrode 175 when the thin-film transistor is in the on state. Thepixel electrode 191 may be made of a transparent metal material such as,for example, indium-tin oxide (ITO) or indium-zinc oxide (IZO).

The pixel electrode 191 includes a transverse stem 193, a longitudinalstem 192 crossing the transverse stem 193, and a plurality of first tofourth minute branches 194 a, 194 b, 194 c, and 194 d.

The transverse stem 193 may be formed in a direction parallel to, orsubstantially parallel to the gate line 121, and the longitudinal stem192 may be formed in a direction parallel to, or substantially parallelto the data line 171. The transverse stem 193 may be positioned at anapproximate center area between the two neighboring gate lines 121, andthe longitudinal stem 192 may be positioned at an approximate centerarea between the two neighboring data lines 171.

One pixel area (P) is divided into a first sub-pixel area, a secondsub-pixel area, a third sub-pixel area, and a fourth sub-pixel area bythe transverse stem 193 and the longitudinal stem 192. Referring to FIG.1, the first sub-pixel area is positioned at the left side of thetransverse stem 193 and at an upper side of the longitudinal stem 192,the second sub-pixel area is positioned at the right side of thetransverse stem 193 and at the upper side of the longitudinal stem 192,the third sub-pixel area is positioned at the left side of thetransverse stem 193 and at the lower side of the longitudinal stem 192,and the fourth sub-pixel area is positioned at the right side of thetransverse stem 193 and at the lower side of the longitudinal stem 192.

The first minute branches 194 a are formed in the first sub-pixel area,the second minute branches 194 b are formed in the second sub-pixelarea, the third minute branches 194 c are formed in the third sub-pixelarea, and the fourth minute branches 194 d are formed in the fourthsub-pixel area.

The first minute branches 194 a are obliquely extended from thetransverse stem 193 or the longitudinal stem 192 in the upper-leftdirection, the second minute branches 194 b are obliquely extended fromthe transverse stem 193 or the longitudinal stem 192 in the upper-rightdirection, the third minute branches 194 c are obliquely extended fromthe transverse stem 193 or the longitudinal stem 192 in the lower-leftdirection, and the fourth minute branches 194 d are obliquely extendedfrom the transverse stem 193 or the longitudinal stem 192 in thelower-right direction.

The first to fourth minute branches 194 a-194 d may form an angle ofabout 45 degrees or about 135 degrees with the gate line 121 or thetransverse stem 193, and the first to fourth minute branches 194 a-194 dof neighboring sub-pixel areas form right angles, or substantially formright angles.

The shape of the pixel electrode 191 is not limited to the shape shownin FIG. 1, and variations are possible according to exemplaryembodiments. Further, the number of sub-pixel areas in a single pixelarea (P) is not limited to four, as shown in FIG. 1. For example,according to exemplary embodiments, a single pixel area (P) may includemore or less than four sub-pixel areas. In addition, the number,orientation, and spacing of the first to fourth minute branches 194a-194 d as shown in FIG. 1 is exemplary, and exemplary embodiments ofthe present invention are not limited thereto.

A common electrode 270 separated from the pixel electrode 191 by apredetermined distance is formed on the pixel electrode 191. A space 200is formed between the pixel electrode 191 and the common electrode 270,and a liquid crystal layer including liquid crystal molecules 3 isformed in the space 200. The liquid crystal molecules 3 may be alignedin a direction perpendicular to, or substantially perpendicular to thesubstrate 110 in the absence of an electric field.

In the exemplary embodiment described above, the pixel electrode 191 isformed at an upper side with reference to the space 200, and the commonelectrode 270 is formed at a lower side with reference to the space 200,however exemplary embodiments of the present invention are not limitedthereto. For example, in an exemplary embodiment, the pixel electrode191 and the common electrode 270 may be both positioned above or underthe space 200. The pixel electrode 191 and the common electrode 270 maybe formed in the same layer, or may be formed in different layers withan insulating layer interposed therebetween. The liquid crystalmolecules 3 formed in the space 200 may be slanted in a directionparallel to, or substantially parallel to the substrate 110.

A first alignment layer 11 is formed on the pixel electrode 191. Thefirst alignment layer 11 may be formed on a portion of the firstinsulating layer 240 that is not covered by the pixel electrode 191.

A second alignment layer 21 facing the first alignment layer 11 isformed under the common electrode 270.

The first alignment layer 11 and the second alignment layer 21 may bevertical alignment layers, and may be made of a material such as, forexample, polyamic acid, polysiloxane, or polyimide. The first and secondalignment layers 11 and 21 may be connected to each other on the edge ofthe pixel area (P).

The space 200 is enclosed by the first insulating layer 240, the pixelelectrode 191, and the common electrode 270. The common electrode 270directly contacts the first insulating layer 240 at the portionoverlapping the data line 171. As a result, the common electrode 270covers the right surface and the left surface of the space 200 in theportion near the data line 171. That is, the common electrode 270encloses the right portion and the left portion of the pixel area (P).The common electrode 270 is connected to the pixel areas (P) neighboringin the row direction.

The common electrode 270 is not connected to the pixel areas (P)neighboring in the column direction. That is, the common electrode 270does not cover most of the upper surface and the lower surface of thespace 200 in the portion neighboring the gate line 121. Accordingly, aliquid crystal injection hole 201 is formed for the space 200 to beexposed to the outside at the upper surface and the lower surface of thespace 200. That is, the liquid crystal injection hole 201 is formedaccording to the gate line 121, and the liquid crystal molecules 3 areinjected inside the space 200 through the liquid crystal injection hole201.

In the exemplary embodiment described above, the common electrode 270covers the left surface and the right surface of the space 200 and doesnot cover the upper surface and the lower surface, however exemplaryembodiments of the present invention are not limited thereto. Forexample, the common electrode 270 may cover other surfaces of the space200. That is, in an exemplary embodiment, the common electrode 270 maycover the lower surface and the upper surface, and not cover the rightsurface and the left surface. The liquid crystal injection hole 201 maybe formed according to the data line 171.

In an exemplary embodiment, an insulating layer made of an inorganicinsulating material such as, for example, silicon nitride (SiNx) orsilicon oxide (SiOx) may be further formed on the common electrode 270.

A roof layer 285 is formed on the common electrode 270. The roof layer285 may be made of an organic material.

A second insulating layer 290 may be further formed on the roof layer285. The second insulating layer 290 may be made of an inorganicinsulating material such as, for example, silicon nitride (SiNx) orsilicon oxide (SiOx). The second insulating layer 290 may cover theentire upper surface and side surface of the roof layer 285. The secondinsulating layer 290 protects the roof layer 285. In exemplaryembodiments, the second insulating layer 290 may not be included.

The common electrode 270 and the roof layer 285 may include a protrusion287 protruding from an upper edge and a lower edge of the pixel area(P). The protrusion 287 protrudes from first and second ends (e.g., aleft end and a right end, respectively) of the upper edge of the pixelarea (P), and first and second ends (e.g., a left end and a right end,respectively) of the lower edge of the pixel area (P).

The protrusion 287 may be triangular. For example, the protrusion 287may include first to fourth protrusions 287 a, 287 b, 287 c, and 287 d,as shown in FIG. 1. The first protrusion 287 a protruding from the firstend (e.g., the left end) of the upper edge of the pixel area (P) mayinclude a first edge extending from the first end of the upper edge ofthe pixel area (P) and a second edge extending from an inner portion ofthe upper edge of the pixel area (P). The first and second edges of thefirst protrusion 287 a form, or substantially form a right-angledtriangle with respect to the portion of the upper edge of the pixel area(P) between the first and second edges. The second protrusion 287 bprotruding from the second end (e.g., the right end) of the upper edgeof the pixel area (P) may include a first edge extending from the secondend of the upper edge of the pixel area (P) and a second edge extendingfrom an inner portion of the upper edge of the pixel area (P). The firstand second edges of the second protrusion 287 b form, or substantiallyform a right-angled triangle with respect to the portion of the upperedge of the pixel area (P) between the first and second edges. The thirdprotrusion 287 c protruding from the first end (e.g., the left end) ofthe lower edge of the pixel area (P) may include a first edge extendingfrom the first end of the lower edge of the pixel area (P) and a secondedge extending from an inner portion of the lower edge of the pixel area(P). The first and second edges of the third protrusion 287 c form, orsubstantially form a right-angled triangle with respect to the portionof the lower edge of the pixel area (P) between the first and secondedges. The fourth protrusion 287 d protruding from the second end (e.g.,the right end) of the lower edge of the pixel area (P) may include afirst edge extending from the second end of the lower edge of the pixelarea (P) and a second edge extending from an inner portion of the loweredge of the pixel area (P). The first and second edges of the fourthprotrusion 287 d form, or substantially form a right-angled trianglewith respect to the portion of the lower edge of the pixel area (P)between the first and second edges.

The second insulating layer 290 covers the upper surface and the sidesurface of the roof layer 285. As a result, the second insulating layer290 may include the protrusion 287 protruding from the upper edge andthe lower edge of the pixel area (P).

The liquid crystal molecules 3 formed in the space 200 are injectedthrough the liquid crystal injection hole 201. The liquid crystalmolecules 3 may be injected via a capillary phenomenon such that the ameniscus is formed near the liquid crystal injection hole 201.

When the liquid crystal injection hole 201 is formed as a straight line,and the meniscus has a shape that is concave towards the inside of theliquid crystal injection hole 201, a region where the liquid crystalmolecules 3 do not exist may be generated at the edges of the pixel area(P), and light leakage may occur in the corresponding portion.

In an exemplary embodiment of the present invention, the commonelectrode 270 and the roof layer 285 include the protrusion 287 on boththe upper edge and the lower edge of the pixel area (P). As a result, aportion of the liquid crystal injection hole 201 may be positionedoutside of the pixel area (P) (e.g., beyond an outer periphery of thepixel area (P)). Accordingly, the meniscus is formed outside of thepixel area (P), and the liquid crystal molecules 3 may fill the entirepixel area, which may reduce or prevent light leakage.

An overcoat 295 may be formed on the second insulating layer 290. Theovercoat 295 covers the liquid crystal injection hole 201 in an areacorresponding to where the space 200 is exposed. That is, the overcoat295 may seal the liquid crystal injection hole 201 such that the liquidcrystal molecules 3 formed inside the space 200 does not flow outsidethe space. The overcoat 295 makes contact with the liquid crystalmolecules 3 in the space 200. Thus, the overcoat 295 is made of amaterial that does not react with the liquid crystal molecules 3. Forexample, the overcoat 295 may be made of a material such as, forexample, parylene. The overcoat 295 may be a thick organic layer,thereby flattening the surface of the substrate 110.

A first polarizer 12 may be formed under the substrate 110, and a secondpolarizer 22 may be further formed on the overcoat 295.

When the second polarizer 22 is formed on the overcoat 295, the secondpolarizer 22 may flatten the upper portion of the overcoat 295.Accordingly, a layer flattening the upper portion of the overcoat 295may be further formed.

Referring to FIG. 4, in an initial state in which an electric field isnot applied to the liquid crystal molecules 3, the liquid crystalmolecules 3 may be slanted in a direction perpendicular to, orsubstantially perpendicular to the edge of the pixel area (P) at theedge of the pixel area (P).

When the polarization axis POL1 of the first polarizer 12 and thepolarization axis POL2 of the second polarizer 22 form an angle of about45 degrees and about 135 degrees with one edge of the pixel area (P), aportion of the light passing through the first polarizer 12 is passedthrough the second polarizer 22 through the liquid crystal molecules 3at the edge of the pixel area (P), potentially resulting in lightleakage.

In an exemplary embodiment of the present invention, the polarizationaxis POL1 of the first polarizer 12 is parallel to, or substantiallyparallel to the upper edge and the lower edge of the pixel area (P), andthe polarization axis POL2 of the second polarizer 22 is parallel to, orsubstantially parallel to the right edge and the left edge of the pixelarea (P). As a result, at the edge of the pixel area (P), the lightpassing through the first polarizer 12 is not passed through the liquidcrystal molecules 3, and light leakage may be reduced or prevented.

Alternatively, in an exemplary embodiment, the polarization axis POL1 ofthe first polarizer 12 may be parallel to the right edge and the leftedge of the pixel area (P), and the polarization axis POL2 of the secondpolarizer 22 may be parallel to the upper edge and the lower edge of thepixel area (P).

In the exemplary embodiment described above, the color filter 230 isformed in the pixel area (P) and the light blocking member 220 is formedon the boundary of the pixel area (P), however exemplary embodiments ofthe present invention are not limited thereto. For example, in anexemplary embodiment, the light blocking member 220 may not be formed,and the color filter 230 formed in the neighboring pixel areas (P) mayextend to the boundary of the pixel area (P) such that color filters 230of two colors overlap each other. The color filters 230 overlapping eachother at the boundary of the pixel area (P) may prevent light leakage.

In addition, in the exemplary embodiment described above, the colorfilter 230 and the light blocking member 220 are formed under the commonelectrode 270, however exemplary embodiments of the present inventionare not limited thereto. For example, in an exemplary embodiment, thecolor filter 230 and the light blocking member 220 may be formed on thecommon electrode 270. Further, in an exemplary embodiment, the rooflayer 285 is not formed, and the color filter 230 and the light blockingmember 220 may include the function of the roof layer 285 as describedabove.

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 5.

The display device according to the exemplary embodiment shown in FIG. 5is similar to the display device described with reference to FIG. 1.Thus, the description of certain similar elements may be omitted. Theshape of the protrusion 287 described with reference to FIG. 5 isdifferent from the shape of the protrusion 287 described with referenceto FIG. 1.

FIG. 5 is a top plan view of a display device according to an exemplaryembodiment of the present invention. The cross-sectional view of thedisplay device according to the exemplary embodiment shown in FIG. 5 issimilar to the cross-sectional view shown in FIGS. 2 and 3.

The elements of the display device according to the exemplary embodimentshown in FIG. 5 may be deposited in a similar sequence as describedabove with reference to FIGS. 1 to 3.

In an exemplary embodiment according to FIG. 5, the protrusion 287protrudes from a center area of the upper edge and lower edge of thepixel area (P), rather than from the first and second ends (e.g., leftand right ends) of the upper edge and lower edge of the pixel area (P).

The protrusion 287 includes first and second protrusions 287 a and 287b. The first protrusion 287 a protruding from the center area of theupper edge of the pixel area (P) may include two edges extending towardseach other from the center area of the upper edge of the pixel area (P).The two edges meet each other outside of the pixel area (P), forming atriangular shape, and form a predetermined angle with respect to theportion of the upper edge of the pixel area (P) between the two edges.The second protrusion 287 b protruding from the center area of the loweredge of the pixel area (P) may include two edges extending towards eachother from the center area of the lower edge of the pixel area (P). Thetwo edges meet each other outside of the pixel area (P), forming atriangular shape, and form a predetermined angle with respect to theportion of the lower edge of the pixel area (P) between the two edges.

A width w1 of the pixel area (P) may be varied according to the size andresolution of the display device. For example, the width w1 may be lessthan about 100 um.

The size of a length 11 of the portion of the upper edge of the pixelarea (P) between the first and second edges of the first protrusion 287a controls the meniscus. The length 11 may be narrower than the width w1of the pixel area (P). For example, in an exemplary embodiment, thelength 11 of the first protrusion 287 a may be at least about 5 um andat most about 100 um.

Further, in an exemplary embodiment, a height h of the first protrusion287 a may be at least about 5 um and at most about 30 um.

In addition, in an exemplary embodiment, the first edge (e.g., the leftedge) of the first protrusion 287 a may form an angle of at least about10 degrees and at most about 80 degrees with the portion of the upperedge of the pixel area (P) between the first and second edges. When thefirst edge (e.g., the left edge) and the second edge (e.g., right edge)of the first protrusion 287 a are symmetrical to each other, the secondedge of the first protrusion 287 a may also form an angle of at leastabout 10 degrees and at most about 80 degrees with the portion of theupper edge of the pixel area (P) between the first and second edges.

Exemplary embodiments of the present invention are not limited to thenumber of first and second protrusions 287 a and 287 b as shown in FIG.5.

In an exemplary embodiment of the present invention, the commonelectrode 270 and the roof layer 285 include the protrusion 287 in thecenter area of the upper edge and the lower edge of the pixel area (P),such that a portion of the liquid crystal injection hole 201 may bepositioned outside of the pixel area (P). Accordingly, the meniscus maybe formed outside of the pixel area (P).

A display device according to exemplary embodiments of the presentinvention will be described with reference to FIGS. 6 and 7.

FIG. 6 is a top plan view of a display device according to an exemplaryembodiment of the present invention. FIG. 7 is a top plan view of adisplay device according to an exemplary embodiment of the presentinvention.

Referring to the exemplary embodiments according to FIGS. 6 and 7, theposition of the protrusion 287 is similar to that of the exemplaryembodiment according to FIG. 5, however the embodiments shown in FIGS. 6and 7 include a protrusion 287 having different shapes.

As shown in FIGS. 6 and 7, the common electrode 270 and the roof layer285 include a protrusion 287 protruding from a center area of the upperedge and the lower edge of the pixel area (P).

The protrusion 287 may be substantially in the shape of a quadrangle.For example, the protrusion 287 may include a first protrusion 287 a anda second protrusion 287 b, each substantially having the shape of aquadrangle. The first protrusion 287 a protruding from the center areaof the upper edge of the pixel area (P) may include two edges extendingfrom, and perpendicular to, or substantially perpendicular to the upperedge of the pixel area (P), as shown in FIG. 6. The second protrusion287 b protruding from the center area of the lower edge of the pixelarea (P) may include two edges extending from, and perpendicular to, orsubstantially perpendicular to the lower edge of the pixel area (P), asshown in FIG. 6.

The width and the height of the protrusion 287 in the exemplaryembodiment shown in FIG. 6 may have values in the range described withreference to the protrusion of the exemplary embodiment described withreference to FIG. 5.

Referring to FIG. 7, the shape of the protrusion 287 of the displaydevice according to an exemplary embodiment may be circular. Forexample, the protrusion 287 may include the first protrusion 287 a andthe second protrusion 287 b, as shown in FIG. 7. The first protrusion287 a may be circular and may protrude from a center area of the upperedge of the pixel area (P). The second protrusion 287 b may be circularand may protrude from the center area of the lower edge of the pixelarea (P).

The diameter of the protrusion 287 in the exemplary embodiment shown inFIG. 7 may have values in the range described with reference to theprotrusion of the exemplary embodiment described with reference to FIG.5.

According to the exemplary embodiments described above, the shape of theprotrusion 287 may be a triangle, a quadrangle, or circular, howeverexemplary embodiments of the present invention are not limited thereto.For example, exemplary embodiments may include a protrusion 287 havingother shapes such as a trapezoid.

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 8.

FIG. 8 is a top plan view of a display device according to an exemplaryembodiment of the present invention.

In the display device according to the exemplary embodiment shown inFIG. 8, the common electrode 270 and the roof layer 285 include aprotrusion 287 protruding from the upper edge and the lower edge of thepixel area (P).

The protrusion 287 includes first to fourth protrusions 287 a, 287 b,287 c, and 287 d, each having a triangular shape. The first protrusion287 a protrudes between a center area of the upper edge of the pixelarea (P) and a first end (e.g., the left end) of the pixel area (P), thesecond protrusion 287 b protrudes between the center area of the upperedge of the pixel area (P) and a second end (e.g., the right end) of thepixel area (P), the third protrusion 287 c protrudes between a centerarea of the lower edge of the pixel area (P) and the first end of thepixel area (P), and the fourth protrusion 287 d protrudes between thecenter area of the lower edge of the pixel area (P) and the second endof the pixel area (P).

The protrusion 287 shown in FIG. 8 includes four triangular protrusions,however exemplary embodiments of the present invention are not limitedthereto. For example, exemplary embodiments may include more than fourtriangular protrusions, or less than four triangular protrusions. In anexemplary embodiment, two protrusions may be formed between the centerarea of the upper edge of the pixel area (P) and the first end of thepixel area (P), and two protrusions may be formed between the centerarea of the upper edge of the pixel area (P) and the second end of thepixel area (P). The same configuration may be included at the lower edgeof the pixel area (P), thereby resulting in a total of eight triangularprotrusions.

Further, exemplary embodiments according to FIG. 8 may include shapesother than triangles. For example, the protrusions may be in the shapeof a quadrangle or a trapezoid, or may be circular.

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 9.

FIG. 9 is a top plan view of a display device according to an exemplaryembodiment of the present invention.

In the display device according to the exemplary embodiment shown inFIG. 9, the common electrode 270 and the roof layer 285 include aprotrusion 287 protruding from the upper edge and the lower edge of thepixel area (P).

The protrusion 287 includes first to sixth triangular protrusions 287 a,287 b, 287 c, 287 d, 287 e, and 287 f. The first to third triangularprotrusions 287 a, 287 b, and 287 c include vertexes meeting each otherat the upper edge of the pixel area (P), and the fourth to sixthprotrusions 287 d, 287 e, and 287 f include vertexes meeting each otherat the lower edge of the pixel area (P).

The first protrusion 287 a may include a first edge extending from thefirst end (e.g., the left end) of the upper edge of the pixel area (P)and a second edge extending from an inner portion of the upper edge ofthe pixel area (P). The first and second edges of the first protrusion287 a form, or substantially form a right-angled triangle with respectto the portion of the upper edge of the pixel area (P) between the firstand second edges. The second protrusion 287 b protrudes from the upperedge of the pixel area (P) to the outside of the pixel area (P), asshown in FIG. 9. The third protrusion 287 c may include a first edgeextending from the second end (e.g., the right end) of the upper edge ofthe pixel area (P) and a second edge extending from an inner portion ofthe upper edge of the pixel area (P). The first and second edges of thethird protrusion 287 c form, or substantially form a right-angledtriangle with respect to the portion of the upper edge of the pixel area(P) between the first and second edges.

The second protrusion 287 b is positioned between the first protrusion287 a and the third protrusion 287 c, and the vertexes of the secondprotrusion 287 b meet the vertex of the first protrusion 287 a and thevertex of the third protrusion 287 c at the upper edge of the pixel area(P), as shown in FIG. 9.

The fourth protrusion 287 d may include a first edge extending from thefirst end (e.g., the left end) of the lower edge of the pixel area (P)and a second edge extending from an inner portion of the lower edge ofthe pixel area (P). The first and second edges of the fourth protrusion287 d form, or substantially form a right-angled triangle with respectto the portion of the lower edge of the pixel area (P) between the firstand second edges. The fifth protrusion 287 e protrudes from the loweredge of the pixel area (P) outside of the pixel area (P). The sixthprotrusion 287 f may include a first edge extending from the second end(e.g., the right end) of the pixel area (P) and a second edge extendingfrom an inner portion of the lower edge of the pixel area (P). The firstand second edges of the sixth protrusion 287 f form, or substantiallyform a right-angled triangle with respect to the portion of the loweredge of the pixel area (P) between the first and second edges.

The fifth protrusion 287 e is positioned between the fourth protrusion287 d and the sixth protrusion 287 f, and the vertexes of the fifthprotrusion 287 e meet the vertex of the fourth protrusion 287 d and thevertex of the sixth protrusion 287 f at the lower edge of the pixel area(P), as shown in FIG. 9.

The protrusion 287 shown in FIG. 9 includes three triangular protrusionshaving vertexes that meet each other at the upper edge of the pixel area(P), and three triangular protrusions having vertexes that meet eachother at the lower edge of the pixel area (P), however exemplaryembodiments of the present invention are not limited thereto. Forexample, in an exemplary embodiment, the protrusion 287 may includethree additional triangular protrusions having vertexes that meet eachother at the upper edge of the pixel area (P), and three additionaltriangular protrusions having vertexes that meet each other at the loweredge of the pixel area (P), thereby resulting in a total of 12triangular protrusions.

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 10

FIG. 10 is a top plan view of a display device according to an exemplaryembodiment of the present invention.

In the display device according to the exemplary embodiment shown inFIG. 10, the common electrode 270 and the roof layer 285 include aprotrusion 287 protruding from the upper edge and the lower edge of thepixel area (P).

The protrusion 287 includes the first and second triangular protrusions287 a and 287 b. Referring to the first protrusion 287 a, the distanceof the protrusion from the upper edge of the pixel area (P) is graduallyincreased as the protrusion gets closer to a center area from the firstand second ends (e.g., the left and right ends) of the upper edge of thepixel area (P). Referring to the second protrusion 287 b, the distanceof the protrusion from the lower edge of the pixel area (P) is graduallyincreased as the protrusion length gets closer to a center area from thefirst and second ends (e.g., the left and right ends) of the lower edgeof the pixel area (P).

A display device according to an exemplary embodiment of the presentinvention will be described with reference to FIG. 11.

FIG. 11 is a top plan view of a display device according to an exemplaryembodiment of the present invention.

The protrusion 287 shown in FIG. 11 includes a first protrusion 287 a ofwhich the distance of the protrusion 287 a from the upper edge of thepixel area (P) is gradually increased as the protrusion 287 a getscloser to a center area from the first and second ends (e.g., the leftand right ends) of the upper edge of the pixel area (P), and a secondprotrusion 287 b of which the distance of the protrusion 287 b from thelower edge of the pixel area (P) is gradually increased as theprotrusion 287 b gets closer to a center area from the first and secondends (e.g., the left and right ends) of the lower edge of the pixel area(P), similar to the exemplary embodiment shown in FIG. 10. However, inthe exemplary embodiment shown in FIG. 11, in the first and secondprotrusions 287 a and 287 b have a circular shape. That is, in theexemplary embodiment shown in FIG. 10, the relationship between thedistance from the edge of the pixel area (P) to the center and theprotrusion is linear, and in the exemplary embodiment shown in FIG. 11,the relationship between the distance from the edge of the pixel area(P) to the center area and the protrusion is non-linear.

A manufacturing method of a display device according to an exemplaryembodiment of the present invention will be described with reference toFIGS. 12 to 23.

The manufacturing method described with reference to FIGS. 12 to 23 maybe used to manufacture the exemplary embodiments described above.Although the manufacturing method described with reference to FIGS. 12to 23 illustrates the manufacture of the display device according to theexemplary embodiment shown in FIG. 1, the manufacturing method is notlimited thereto, and may be utilized to manufacture the display deviceaccording to all of the exemplary embodiments described above. That is,the manufacturing method may be utilized to manufacture display devicesincluding different numbers of protrusions, and protrusions havingdifferent sizes and shapes. The number of protrusions, and the sizes andshapes of the protrusions may be adjusted by changing the shape of themask used in the manufacturing method.

FIGS. 12, 14, 16, 18, 20, and 22 are processing plan views of amanufacturing method of a display device, according to an exemplaryembodiment of the present invention. FIGS. 13, 15, 17, 19, 21, and 23are processing cross-sectional views of a manufacturing method of adisplay device, taken along the lines X-X, XI-XI, XII-XII, XIII-XIII,XIV-XIV, and XV, shown in FIGS. 12, 14, 16, 18, 20, and 22,respectively, according to an exemplary embodiment of the presentinvention.

As shown in FIGS. 12 and 13, a gate line 121 extending in one directionand a gate electrode 124 protruding from the gate line 121 are formed ona substrate 110 may be made of, for example, glass or plastic. Inaddition, a storage electrode 133 separated from the gate line 121 andthe gate electrode 124 is formed. The storage electrode 133 may beformed using the same material as the gate line 121 and the gateelectrode 124.

Next, a gate insulating layer 140 made of an inorganic insulatingmaterial such as, for example, silicon oxide or silicon nitride, isformed on an entire surface of the substrate 110 including the gate line121, the gate electrode 124, and the storage electrode 133, as shown inFIG. 13. The gate insulating layer 140 may be a single layer or amultilayer.

As shown in FIGS. 14 and 15, a semiconductor material such as, forexample, amorphous silicon, polycrystalline silicon, or a metal oxide,is deposited on the gate insulating layer 140 and patterned to form asemiconductor layer 150. The semiconductor layer 150 may be positionedon the gate electrode 124.

Next, a metal material is deposited and patterned to form a data line171 extending in the other direction. Also, a source electrode 173protruding from the data line 171 on the semiconductor layer 150, and adrain electrode 175 separated from the source electrode 173 are formed.The metal material may be a single layer or a multilayer.

After forming the semiconductor layer 150 by patterning thesemiconductor material, the data line 171, the source electrode 173, andthe drain electrode 175 are formed by depositing and patterning themetal material, however exemplary embodiments of the present inventionare not limited thereto.

That is, the semiconductor material and the metal material may becontinuously deposited and simultaneously patterned to form thesemiconductor layer 150, the data line 171, the source electrode 173,and the drain electrode 175. The semiconductor layer 150 extend underthe data line 171.

The gate electrode 124, the semiconductor layer 150, the sourceelectrode 173, and the drain electrode 175 form one thin-filmtransistor. The gate line 121 and the data line 171 may be crossed, anda plurality of pixel areas (P) may be defined by the gate line 121 andthe data line 171.

As shown in FIGS. 16 and 17, a passivation layer 180 is formed on thedata line 171, the source electrode 173, the drain electrode 175, andthe semiconductor layer 150 exposed between the source electrode 173 andthe drain electrode 173. The passivation layer 180 may be made of, forexample, an organic insulating material or an inorganic insulatingmaterial, and may be a single layer or a multilayer.

Next, a color filter 230 is formed in each pixel area (P) on thepassivation layer 180. The color filters 230 of the same color may beformed according to the column direction of a plurality of pixel areas(P). For example, when forming the color filter 230 of three colors, thecolor filter 230 of the first color is first formed, and then the colorfilter 230 of the second color is formed by shifting a mask. Next, afterforming the color filter 230 of the second color, the color filter 230of the third color may be formed by shifting the mask again.

Next, a light blocking member 220 is formed on the thin-film transistorand the boundary of each pixel area (P) on the passivation layer 180.

According to exemplary embodiments of the present invention, the lightblocking member 220 may be formed either before or after the formationof the color filter 230.

Next, the first insulating layer 240, which may be made of, for example,an inorganic insulating material such as silicon nitride (SiNx) orsilicon oxide (SiOx), is formed on the color filter 230 and the lightblocking member 220.

The first insulating layer 240, the light blocking member 220, and thepassivation layer 180 are then etched to form a contact hole 181exposing a portion of the drain electrode 175.

Next, a transparent metal material such as, for example, indium-tinoxide (ITO) or indium-zinc oxide (IZO), is deposited and patterned onthe first insulating layer 240 to form a pixel electrode 191 in thepixel area (P). The pixel electrode 191 is connected to the drainelectrode 175 through the contact hole 181.

As shown in FIG. 18 and FIG. 19, a sacrificial layer 210 made of anorganic insulating material is formed on the pixel electrode 191 and thefirst insulating layer 240. The sacrificial layer 210 is patterned to bedivided between the pixel areas (P) in one direction, and to beconnected according to the pixel areas (P) neighboring in the otherdirection. For example, the sacrificial layer 210 may be separatedbetween the pixel areas (P) neighboring in the row direction, and may beconnected according to the pixel areas (P) neighboring in the columndirection. The sacrificial layer 210 formed on the data line 171 may beremoved.

The sacrificial layer 210 may be made of for example, a photosensitivepolymer material, and the sacrificial layer 210 may be patterned byperforming a photo-process.

As shown in FIGS. 20 and 21, a metal material is deposited on thesacrificial layer 210 to form a common electrode 270. At this time, thecommon electrode 270 covers the entire surface of the substrate 110.

Next, a roof layer 285 made of an organic material is formed on thecommon electrode 270. The roof layer 285 is patterned to remove the rooflayer 285 positioned between the pixel areas (P) neighboring in thecolumn direction, such that the roof layer 285 is connected according tothe pixel areas (P) neighboring in the row direction. Further, the rooflayer 285 is patterned to include a protrusion 287 protruding from theupper edge and the lower edge of the pixel area (P).

At this time, the protrusion 287 is formed to include four triangularprotrusions protruding from the first and second ends (e.g., the leftand right ends) of the upper edge of the pixel area (P) and the firstand second ends (e.g., the left and right ends) of the lower edge of thepixel area (P), as shown in FIG. 20. That is, the protrusion 287 mayinclude first to fourth protrusions 287 a, 287 b, 287 c, and 287 d. Thefirst protrusion 287 a protruding from the first end (e.g., the leftend) of the upper edge of the pixel area (P) may include a first edgeextending from the first end of the upper edge of the pixel area (P),and a second edge extending from an inner portion of the upper edge ofthe pixel area (P). The first and second edges of the first protrusion287 a form, or substantially form a right-angled triangle with respectto the portion of the upper edge of the pixel area (P) between the firstand second edges. The second protrusion 287 b protruding from the secondend of the upper edge of the pixel area (P) may include a first edgeextending from the second end of the upper edge of the pixel area (P),and a second edge extending from an inner portion of the upper edge ofthe pixel area (P). The first and second edges of the second protrusion287 b form, or substantially form a right-angled triangle with respectto the portion of the upper edge of the pixel area (P) between the firstand second edges. The third protrusion 287 c protruding from the firstend of the lower edge of the pixel area (P) may include a first edgeextending from the first end of the pixel area (P), and a second edgeextending from an inner portion of the lower edge of the pixel area (P).The first and second edges of the third protrusion 287 c form, orsubstantially form a right-angled triangle with respect to the portionof the lower edge of the pixel area (P) between the first and secondedges. The fourth protrusion 287 d protruding from the second end of thelower edge of the pixel area (P) may include a first edge extending fromthe second end of the pixel area (P), and a second edge extending froman inner portion of the lower edge of the pixel area (P). The first andsecond edges of the fourth protrusion 287 d form, or substantially forma right-angled triangle with respect to the portion of the lower edge ofthe pixel area (P) between the first and second edges.

As shown in FIGS. 22 and 23, the second insulating layer 290, which ismade of an inorganic insulating material such as, for example, siliconnitride (SiNx) or silicon oxide (SiOx), may be formed on the roof layer285.

Next, the second insulating layer 290 and the common electrode 270 arepatterned to remove the common electrode 270 and the second insulatinglayer 290 positioned between the pixel areas (P) neighboring in thecolumn direction. As a result, the common electrode 270 is connectedaccording to the pixel areas (P) neighboring in the row direction. Inaddition, the common electrode 270 is formed to include a protrusion 287protruding from the upper edge and the lower edge of the pixel area (P).

The mask used for patterning the roof layer 285 and the mask used forpatterning the common electrode 270 may be the same mask. As a result,the roof layer 285 and the common electrode 270 may have substantiallythe same shape. However, as shown in FIG. 23, the second insulatinglayer 290 may cover the side surface of the roof layer 285 such that thecommon electrode 270 has a boundary positioned outside of the roof layer285.

The common electrode 270 is patterned to include first to fourthprotrusions 287 a, 287 b, 287 c, and 287 d protruding from the upperedge and the lower edge of the pixel area (P), as shown in FIG. 22.

The sacrificial layer 210 positioned under a portion where the commonelectrode 270 is removed is exposed. In exemplary embodiments, oxygenplasma for ashing is supplied on the substrate 110 where the sacrificiallayer 210 is exposed, or a developing solution is supplied to remove theentire surface of the sacrificial layer 210. If the sacrificial layer210 is removed, a space 200 is created at a position where thesacrificial layer 210 is positioned. That is, the pixel electrode 191and the common electrode 270 are separated with the space 200 interposedtherebetween.

Further, the space 200 is exposed through a portion where the commonelectrode 270 and the roof layer 285 are not formed. This area isreferred to as a liquid crystal injection hole 201. The liquid crystalinjection hole 201 may be formed according to the direction of the gateline 121. Alternatively, in an exemplary embodiment, the liquid crystalinjection hole 201 may be formed according to the direction of the dataline 171.

In an exemplary embodiment, the liquid crystal injection hole 201 ispositioned closer to the upper edge and the lower edge of the pixel area(P), and the common electrode 270 and the roof layer 285 include theprotrusion 287 such that a portion of the liquid crystal injection hole201 is positioned outside of the pixel area (P) (e.g., beyond an outerperiphery of the pixel area (P)). That is, at the left and right ends ofthe upper edge and lower edge of the pixel area (P), the liquid crystalinjection hole 201 is positioned outside the pixel area (P), and as aresult, the meniscus of the liquid crystal layer is formed outside ofthe pixel area (P).

Next, an aligning agent including an alignment material is deposited onthe substrate 110 using, for example, a spin coating method or an inkjetmethod, to inject the aligning agent inside the space 200 through theliquid crystal injection hole 201. After injecting the aligning agentinside the space 200, a hardening process is performed to evaporate asolution component and to maintain the alignment material on the innerwall of the space 200.

Accordingly, the first alignment layer 11 may be formed on the pixelelectrode 191, and the second alignment layer 21 may be formed under thecommon electrode 270. The first alignment layer 11 and the secondalignment layer 21 are formed such that they face to each other via thespace 200, and are connected to each other at the edge of the pixel area(P). That is, the common electrode 270 forms a side wall covering theside surface of the space 200 in the direction parallel to the data line171 in the portion near the data line 171, and the alignment material ismaintained on the inner surface of the side wall.

At this time, the first and second alignment layers 11 and 21 performalignment in the direction perpendicular to the first substrate 110,except for the side surface of the space 200. In addition, by performinga process of irradiating ultraviolet rays to the first and secondalignment layer 11 and 21, alignment may be performed in the directionparallel to the substrate 110.

Next, liquid crystal molecules 3 are deposited by the inkjet method orthe dispensing method on the substrate 110 such that the liquid crystalmolecules 3 are injected inside the space 200 through the liquid crystalinjection hole 201. At this time, the liquid crystal molecules 3 may bedeposited via the liquid crystal injection hole 201 formed according tothe odd-numbered gate lines 121, and may not be deposited via the liquidcrystal injection hole 201 formed according to the even-numbered gatelines 121. Alternatively, the liquid crystal molecules 3 may bedeposited via the liquid crystal injection hole 201 formed according tothe even-numbered gate lines 121, and may not be deposited via theliquid crystal injection hole 201 formed according to the odd-numberedgate lines 121.

If the liquid crystal molecules 3 are deposited via the liquid crystalinjection hole 201 formed according to the odd-numbered gate lines 121,the liquid crystal molecules 3 may be injected inside the space 200through the liquid crystal injection hole 201 by capillary force. Atthis time, air inside the space 200 flows out through the liquid crystalinjection hole 201 formed according to the even-numbered gate lines 121,allowing the liquid crystal molecules 3 to be injected inside the space200.

Next, a material that does not react with the liquid crystal molecules 3is deposited on the second insulating layer 290 to form an overcoat 295.The overcoat 295 is formed to cover the liquid crystal injection hole201 in an area where the space 200 is exposed, and to seal the space 200for each pixel area (P). The overcoat 295 may be formed of a materialthat does not react with the liquid crystal 3 molecules such as, forexample, parylene.

The overcoat 295 may be thickly formed, or an organic insulator may beadditionally formed on the overcoat 295 to flatten the substrate 110.

Next, the first polarizer 12 may be formed under the substrate 110, andthe second polarizer 22 may be formed on the overcoat 295. The secondpolarizer 22 may be formed after flattening the upper portion of theovercoat 295.

In exemplary embodiments, forming the second polarizer 22 on theovercoat 295 may be omitted.

While the present invention has been particularly shown and describedwith reference to the exemplary embodiments thereof, it will beunderstood by those of ordinary skill in the art that various changes inform and detail may be made therein without departing from the spiritand scope of the present invention as defined by the following claims.

What is claimed is:
 1. A display device, comprising: a substratecomprising a pixel area; a thin-film transistor formed on the substrate;a pixel electrode connected to the thin-film transistor; a commonelectrode formed on the pixel electrode; a space formed between thepixel electrode and the common electrode; and a roof layer formed on thecommon electrode, wherein the common electrode and the roof layercomprise a protrusion protruding from at least one of an upper edge anda lower edge of the pixel area.
 2. The display device of claim 1,wherein the roof layer comprises an organic material.
 3. The displaydevice of claim 1, wherein the pixel area is one of a plurality of pixelareas, and the pixel areas are disposed in a matrix shape, and thecommon electrode and the roof layer cover an upper surface, a leftsurface, and a right surface of the space.
 4. The display device ofclaim 3, further comprising: an overcoat formed on the roof layer andsealing the space; a liquid crystal injection hole exposing the space atthe upper edge and the lower edge of the pixel area; and liquid crystalmolecules formed in the space, wherein the overcoat covers the liquidcrystal injection hole.
 5. The display device of claim 4, furthercomprising: a first polarizer formed under the substrate; and a secondpolarizer formed on the overcoat, wherein a transmissive axis of one ofthe first polarizer and the second polarizer is substantially parallelto the upper edge and the lower edge of the pixel area, and atransmissive axis of the other of the first polarizer and the secondpolarizer is substantially perpendicular to the upper edge and the loweredge of the pixel area.
 6. The display device of claim 1, wherein theprotrusion is triangular, and the protrusion protrudes from a first endof the upper or lower edge of the pixel area, or a second end of theupper or lower edge of the pixel area, wherein the first and second endsoppose each other.
 7. The display device of claim 6, wherein theprotrusion comprises a first edge extending from the first or second endof the upper or lower edge of the pixel area, and a second edgeextending from an inner portion of the upper or lower edge of the pixelarea.
 8. The display device of claim 7, wherein the first and secondedges of the protrusion substantially form a right-angled triangle withrespect to a portion of the upper or lower edge of the pixel areabetween the first and second edges of the protrusion.
 9. The displaydevice of claim 1, wherein the protrusion protrudes from a center areaof the upper or lower edge of the pixel area, and the protrusion istriangular, quadrangular, or circular.
 10. The display device of claim9, wherein the protrusion is triangular and comprises a first edge and asecond edge, each edge extending from the upper or lower edge of thepixel area, a length of a portion of the upper or lower edge of thepixel area between the first and second edge of the protrusion is atleast about 5 um and at most about equal to a width of the pixel area, aheight of the protrusion is at least about 5 um and at most about 30 um,and the first and second edge of the protrusion each forms an angle ofat least about 10 degrees and at most about 80 degrees with the upper orlower edge of the pixel area.
 11. The display device of claim 1, whereinthe protrusion is triangular and protrudes between a center area of theupper or lower edge of the pixel area and a first end of the pixel area,or between the center area of the upper or lower edge of the pixel areaand a second end of the pixel area, wherein the first and second ends ofthe pixel area oppose each other.
 12. The display device of claim 1,wherein the protrusion comprises a plurality of triangular protrusionsprotruding from the upper or lower edge of the pixel area, and vertexesof the triangular protrusions meet each other at the upper or lower edgeof the pixel area.
 13. The display device of claim 1, wherein a distanceof the protrusion from the upper or lower edge of the pixel areagradually increases as the protrusion extends from an end of the upperor lower edge of the pixel area towards a center area of the upper orlower edge of the pixel area.
 14. The display device of claim 13,wherein the protrusion is triangular or a circular.
 15. The displaydevice of claim 1, wherein the protrusion protrudes from the upper edgeand the lower edge of the pixel area.
 16. A method of manufacturing adisplay device, comprising: forming a thin-film transistor on asubstrate comprising a pixel area; forming a pixel electrode in thepixel area; forming a sacrificial layer on the pixel electrode; forminga common electrode covering an upper surface, a left surface, and aright surface of the sacrificial layer; forming a roof layer on thecommon electrode; forming a liquid crystal injection hole by patterningthe roof layer and the common electrode and exposing the sacrificiallayer on an upper edge of the pixel area and a lower edge of the pixelarea; removing the sacrificial layer to form a space between the pixelelectrode and the common electrode; injecting liquid crystal moleculesinto the space through the liquid crystal injection hole; and forming anovercoat on the roof layer, wherein the overcoat and the commonelectrode are patterned such that the overcoat and the common electrodecomprise a protrusion protruding from at least one of the upper edge andthe lower edge of the pixel area.
 17. The method of claim 16, whereinthe protrusion is triangular, and the protrusion protrudes from a firstend of the upper or lower edge of the pixel area, or a second end of theupper or lower edge of the pixel area, wherein the first and second endsoppose each other.
 18. The method of claim 17, wherein the protrusioncomprises a first edge extending from the first or second end of theupper or lower edge of the pixel area, and a second edge extending froman inner portion of the upper or lower edge of the pixel area.
 19. Themethod of claim 18, wherein the first and second edges of the protrusionsubstantially form a right-angled triangle with respect to a portion ofthe upper or lower edge of the pixel area between the first and secondedges of the protrusion.
 20. The method of claim 16, wherein theprotrusion protrudes from a center area of the upper or lower edge ofthe pixel area, and the protrusion is triangular, quadrangular, orcircular.
 21. The method of claim 20, wherein the protrusion istriangular and comprises a first edge and a second edge, each edgeextending from the upper or lower edge of the pixel area, a length of aportion of the upper or lower edge of the pixel area between the firstand second edge of the protrusion is at least about 5 um and at mostabout equal to a width of the pixel area, a height of the protrusion isat least about 5 um and at most about 30 um, and the first and secondedge of the protrusion each forms an angle of at least about 10 degreesand at most about 80 degrees with the upper or lower edge of the pixelarea.
 22. The method of claim 16, wherein the protrusion is triangularand protrudes between a center area of the upper or lower edge of thepixel area and a first end of the pixel area, or between the center areaof the upper or lower edge of the pixel area and a second end of thepixel area, wherein the first and second ends of the pixel area opposeeach other.
 23. The method of claim 16, wherein the protrusion comprisesa plurality of triangular protrusions protruding from the upper or loweredge of the pixel area, and vertexes of the triangular protrusions meeteach other at the upper or lower edge of the pixel area.
 24. The methodof claim 16, wherein a distance of the protrusion from the upper orlower edge of the pixel area gradually increases as the protrusionextends from an end of the upper or lower edge of the pixel area towardsa center area of the upper or lower edge of the pixel area.
 25. Themethod of claim 24, wherein the protrusion is triangular or circular.26. The method of claim 16, further comprising: forming a firstpolarizer on the substrate; and forming a second polarizer on theovercoat, wherein a transmissive axis of one of the first polarizer andthe second polarizer is substantially parallel to the upper edge and thelower edge of the pixel area, and a transmissive axis of the other oneof the first polarizer and the second polarizer is substantiallyperpendicular to the upper edge and the lower edge of the pixel 7 area.27. The method of claim 16, wherein the protrusion protrudes from theupper edge and the lower edge of the pixel area.
 28. A pixel area of adisplay device, comprising: a pixel electrode; a common electrode; and aliquid crystal layer disposed between the pixel electrode and the commonelectrode, wherein a meniscus of the liquid crystal layer extends beyondan outer periphery of the pixel area.
 29. The pixel area of claim 28,further comprising: a liquid crystal injection hole disposed in theliquid crystal layer, wherein the liquid crystal injection hole isdisposed beyond the outer periphery of the pixel area.
 30. The pixelarea of claim 28, wherein the common electrode comprises a protrudingportion extending outward from an upper edge or a lower edge of thepixel area, and the protruding portion comprises the meniscus.